A suspension device is interposed between a vehicle body and a wheel in a vehicle in general. In the suspension device, a suspension spring for elastically supporting the vehicle body and a shock absorber generating a damping force for suppressing an extension/contraction motion of this suspension spring are provided in parallel. The suspension device suppresses transmission of an impact caused by irregularity on a road surface to the vehicle body and makes riding comfort of the vehicle favorable.
As disclosed in JP2008-175369A, shock absorbers used for the suspension device for an automobile include a magnetic viscous fluid shock absorber using a magnetic viscous fluid whose viscosity changes by an action of a magnetic field as an operating fluid.